Insufflation/exsufflation airway clearance apparatus

ABSTRACT

An MIE apparatus has a blower, a valve system, and a mask hose connector. The blower is connected to the valve system which is connected to the hose connector. During insufflation, the valve system connects exhaust of the blower to the hose connector to cause positive pressure at the hose connector. During exsufflation, the valve system connects the blower intake to the hose connector to cause negative pressure at the hose connector. The apparatus has an automatic mode in which switching between insufflation and exsufflation is based on one or more preset time intervals and a manual mode in which switching between insufflation and exsufflation is based on a manual input from a user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/957,473, filed Aug. 2, 2013, now U.S. Pat. No. ______, which is acontinuation of U.S. application Ser. No. 13/107,463, filed May 13,2011, now U.S. Pat. No. 8,539,952, each of which is hereby expresslyincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical devices, more particularly, todevices that aid in breathing and in inducing coughs.

2. Description of the Related Art

Professionals using mechanical Insufflators/Exsufflators (MIEs) haverealized over the years that there are serious limitations to currentmachines. There have been no real improvement in MEI functionality in 50years.

Parents of pediatric patients, as well as many adult patients, take themachine everywhere with them. Size and weight are a problem.

MEIs typically operated on 120 volts AC. In order to operate in manyvehicles with a 12 volt DC system, inverters have to be installed, whichare expensive and complicated to install.

A major concern of the medical community is the use of an MIE on sickerpatients with compromised lung function and reduced functional residualcapacity because current MIEs do not incorporate positive end expiratorypressure on the expiratory phase.

For many patients with thick secretions, current MIEs need a greatamount of time and additional intervention to mobilize and remove them.

Many pediatric, elderly, and stroke patients have difficultysynchronizing with the breathing pattern of the current MIEs.

BRIEF SUMMARY OF THE INVENTION

The MIE apparatus of the present invention has a case that houses anadjustable speed blower, a valve subassembly with a direction valve andan oscillator, a hose connector, a controller, a power supply, and atouch screen.

The blower intake is connected to an intake port on the direction valveand the blower exhaust is connected to the exhaust port on the directionvalve. The common port of the direction valve is connected to the valveport of the oscillator and the connector port of the oscillator isconnected to the mask hose connector. The air flow path between theblower and the hose connector is the channel.

The apparatus has two primary modes: insufflation and exsufflation. Ininsufflation mode, the direction valve connects the blower exhaust tothe oscillator, causing positive pressure at the hose connector. Inexsufflation mode, the direction valve connects the blower intake to theoscillator, causing negative pressure at the hose connector. To induce acough, the apparatus starts in the insufflation mode to fill the lungsand then quickly switches to exsufflation mode, rapidly deflating thelungs and thereby stimulating a cough.

The oscillator is a butterfly valve with a chamber and a 360° rotatingdisc within the chamber. During the insufflation, the disc is rotated toa stationary position of high, medium, or low flow rate to modulate theairflow. In the high position, the disc is parallel to the channel and,at the low flow rate, the disc is almost perpendicular to the channel.

During exsufflation, the oscillator is either inactive or is in a“flutter” mode. If inactive, the disc is parallel to the channel tomaximize airflow. In flutter mode, the disc is continuously rotated,causing the channel size to rapidly change from a maximum flow rate tominimal flow rate and back.

The apparatus can operation in manual mode or automatic mode. In manualmode, the user controls when and how a treatment cycle occurs bypressing the associated buttons on the touch screen or on the remotecontrol. In automatic mode, the apparatus repeatedly initiates treatmentcycles, which is an insufflation followed by an exsufflation followed bya rest.

For manual mode, the insufflation pressure, the exsufflation pressure,the rest pressure, the flow rate, and the flutter frequency can be set.For automatic mode, in addition to the manual mode parameters, theinsufflation time, the exsufflation time, the rest time, and the numberof cycles can be set.

In manual mode, the patient touches a start/stop button to turn theblower on. An insufflation is initiated by actuating an inhale button onthe touch screen or remote and is maintained until the button isreleased. An exsufflation is initiated by actuating an exhale button onthe touch screen or remote and is maintained until the button isreleased. When treatment is complete, the patient touches a start/stopbutton to turn the blower off.

In automatic mode, the patient touches a start/stop button to turn theblower on and to begin the treatment cycles. When the set number of thetreatment cycles is reached, the apparatus discontinues treatment andturns the blower off.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and object of the presentinvention, reference is made to the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of the apparatus of the present invention;

FIG. 2 is a front, perspective view of the apparatus;

FIG. 3 is a back view of the apparatus of FIG. 2;

FIG. 4 is top view with the case top removed;

FIG. 5 is a top, cross-sectional view of the valve subassembly;

FIG. 6 is a side, cross-sectional view of the valve subassembly;

FIG. 7 is an example display for manual mode;

FIG. 8 is an example display for automatic mode;

FIG. 9 is an example display for configuration;

FIG. 10 is a flow diagram of the operation of the apparatus in manualmode; and

FIG. 11 is a flow diagram of the operation of the apparatus in automaticmode.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is an apparatus for assisting in coughing. Onefeature of the present invention is the ability to vibrate the airway.Vibration of the airway at a specific frequency creates the phenomenonknown as “enhanced diffusivity”. This mechanism changes the rate ofdiffusion in the alveolar-capillary membrane of the lung. By changingthe diffusion coefficient in the lung, greater amounts of oxygen can beput into the blood stream and greater amounts of carbon dioxide can beremoved. The special valve that creates this function is a rotatingbutterfly-type mechanism which has an adjustable frequency forconforming to specific pulmonary physiologies.

Another feature is the ability to use the apparatus to recruit lungvolume. The apparatus uses a mechanism to gradually adjust the basepressure at the end of exsufflation. This creates a degree of positivepressure inside the lung thereby helping the lung to reinflate whenvital capacity has been decreased due to pulmonary compromise. The basepressure is adjustable from 0 to 15 cm H₂O depending on the degree ofcompromise

The cough assist apparatus 10 of the present invention is shown in FIGS.1-9. The case 12 houses a blower 14, a valve subassembly 16, a hoseconnector 18, a controller 20, a power supply 22, and a touch screen 24.The valve subassembly 16 includes a direction valve 28 and an oscillator30.

An overall diagram of the apparatus 10 is shown in FIG. 1. The blower 14has an intake 40 where air enters the blower 14 and an exhaust 42 whereair exits the blower 14. The blower intake 40 is connected to the intakeport 48 of direction valve 28 via an intake duct 44. The blower exhaust42 is connected to the exhaust port 50 of the direction valve 28 via anexhaust duct 46. The common port 52 of the direction valve 28 isconnected to the valve port 60 of the oscillator 30. The atmosphere port54 of the direction valve 28 is open to atmosphere, as at 56, and has anoptional filter 58. The connector port 62 of the oscillator 30 isconnected to the patient interface (mask) hose connector 18. The path ofair flow between the blower 14 and the hose connector 18 is referred toas the channel 36. The controller 20 controls the operation of theapparatus 10. A power supply 20 provides power to the components. Eachcomponent of the apparatus 10 is described in detail below.

When in use, a hose 32 is attached to the apparatus 10. One end 66 ofthe hose 32 attaches to the apparatus 10 at the hose connector 18. Themask 34 is attached to the other end 68 of the hose 32.

The apparatus 10 has two primary modes: insufflation and exsufflation,that is, inhale and exhale relative to the patient. To induce a cough,the apparatus 10 starts in the insufflation mode to fill the lungs. Theapparatus 10 then rapidly transitions to exsufflation mode, rapidlydeflating the lungs and thereby stimulating a cough.

The case 12 houses and protects the operational components of theapparatus 10. Accessible from the outside of the case 12 are the touchscreen 24, hose connector 18, remote control connector 98, a power inputconnector 78, and power switch 82. Optionally, the touch screen 24 has aresilient protective cover 80.

The blower 14 used in the present configuration is a standard motorizedblower with an adjustable speed. It has an intake 40 for suction and anexhaust 42 for blowing. The speed of the blower 14 is controlled byvarying the voltage at a control input. The blower 14 is capable ofproviding a flow rate of up to 12.4 liters/sec.

The setting of the direction valve 28 determines the direction ofairflow to the hose connector 18 and, ultimately, the mask 34. Ininsufflation mode, the direction valve 28 connects the blower exhaust 42to the oscillator 30, causing a positive flow at the hose connector 18,and connects the blower intake 40 to atmosphere, as at 56, as a sourceof air for the blower 14. In exsufflation mode, the direction valve 28connects the blower intake 40 to the oscillator 30, causing a negativeflow at the hose connector 18, and connects the blower exhaust 42 toatmosphere, as at 56, for pressure relief. The controller 20 operatesthe direction valve 28 by a two-position stepper motor 74.

The oscillator 30 is a butterfly valve with a chamber 86 between thevalve port 60 and connector port 62 and a rotating disc 88 within thechamber 86. The disc 88 rotates 360° and is controlled by the controller20 using a stepper motor 76. The controller 20 modulates the opening ofthe channel 36 by rotating the disc 88 to various positions. The steppermotor 76 in the current implementation has a resolution of 0.9° perstep, so the disc 88 can be positioned in increments of 0.9°. Since thesize of the channel 36 directly affects the magnitude of flow, theoscillator 30 adjusts the flow throughout a given procedure. Typically,it is used as follows.

During the insufflation mode, the oscillator 30 modulates the airflow.The disc 88 is rotated to a stationary position of high, medium, or lowflow rates. In the high position, the disc 88 is parallel to the channel36, thus maximizing the channel size. This minimizes the resistance toflow, thereby maximizing the flow rate going to the patient. At the lowflow rate, the disc 88 is almost perpendicular to the channel 36, thusminimizing the channel size. This creates the most resistance to flow,thereby minimizing the flow rate to the patient. Adjustment of thisairflow setting determines how fast the patient's lungs fill up duringinhale.

During exsufflation mode, the oscillator 30 is either inactive or is ina “flutter” mode. If the oscillator 30 is inactive, the disc 88 isrotated until it is parallel to the channel 36 in order to maximizeairflow. Since the productiveness of a cough is directly attributable tothe magnitude of exsufflation flow, airflow is maximized during exhale.

In flutter mode, the oscillator 30 creates a flow that rapidly changesduring exsufflation. To do this, the disc 88 is continuously rotated,causing the channel size to rapidly change from a maximum flow rate tominimal flow rate and back. This airflow rate from maximum to minimum isvaried by simply adjusting the rotation frequency. “Fluttering” the flowrate during exsufflation assists in the dislodging of mucus in thepulmonary airways.

As indicated above, the size of the channel 36 directly affects theairflow. In the present implementation, the size of the channel 36 is19.6 mm, which is measured at the inside diameter at the connector port62 of the oscillator 30. The blower 14 is capable of providing a flowrate of up to 12.4 liters/sec. The airflow is affected by the length anddiameter of the channel 36 between the blower and the patient, as wellas the position of the disc 88 in the oscillator 30. Due to theparameters of the channel 36 in the present implementation, air flowdramatically decreases by the time it reaches the patient. In thepresent implementation, a flow rate of 12.4 liters/sec at the blower 14results in a flow rate at the patient of about 9 liters/sec. The minimumflow to create a productive cough is about 6 liters/sec (mean peakexpiratory flow rate) at the patient.

The controller 20 has a processor 102 which includes its attendantclock, memory, input/output devices, etc. The processor 102 sendssignals to drivers that provide control signals to various components.Various sensors notify the processor 102 of the conditions within theapparatus 10. The processor 102 controls the blower 14 through a powerdriver 108 and a speed driver 110. The processor 102 controls thedirection valve 28 through the direction valve motor driver 104 and thedirection valve position encoder 124. The processor 102 controls theoscillator 30 through the oscillator motor driver 106 and the oscillatorposition encoder 126. Other sensors include the blower temperaturesensor 112, the channel air temperature sensor 116 and the channel airpressure sensor 120. The speaker 26, mounted on the floor of the case12, is controlled by the speaker driver 122 and the touch screen 24 iscontrolled by the touch screen driver 128. The touch screen 24 is adisplay as well as a user input device.

The power supply 22 provides power to the apparatus 10 through an ACpower cord connected to the power input connector 78. Optionally, thepower supply 22 is capable of providing power from an internal battery92 or an external DC source, such as an automobile power outlet orexternal battery, through a DC source connector 94.

Optionally, the apparatus 10 includes a remote control 96. The remotecontrol 96 can be wired, as in FIG. 2, or wireless. The wired remotecontrol plug 99 plugs into the apparatus 10 through a remote controljack 98. The remote control 96 operates all or a subset of the functionsof the apparatus 10. The simple remote control 96 of FIG. 2 has a singlerocker switch 97 to control an insufflate/exsufflate cycle. The remotecontrol 96 can be hand operated or foot operated.

Software running on the processor 102 controls the operation of theapparatus 10. The software controls the treatment cycles and a cycle isdefined as an insufflation, an exsufflation, and a rest. A treatmentcycle has a number of settable parameters associated with it, asfollows.

The manual/automatic setting determines whether the apparatus 10 is tooperate in manual mode or automatic mode. In manual mode, the usercontrols when and how a treatment cycle occurs by pressing theassociated buttons on the touch screen 24 or on the remote control 96.In automatic mode, the apparatus 10 repeatedly initiates treatmentcycles. For both modes, the user can set insufflation/exsufflationpressures, flow, and flutter.

Shown in FIG. 7 is an example display 140 for manual mode.

The insufflation pressure 150, the positive pressure of the air beingpushed into the lungs, can be set in the range of 0-50 cmH₂O in 1 cmH₂Oincrements using an increase arrow 152 and decrease arrow 154. Theexsufflation pressure 158, the negative pressure of the air being pulledfrom the lungs, can be set in the range of 0-50 cmH₂O in 1 cmH₂Oincrements using an increase arrow 160 and decrease arrow 162.

The flow rate can be set to high, medium, or low via button 148. Inhigh, the disc 88 sits parallel to the channel 36, maximizing the flowrate to the patient. In medium, the disc 88 sits at about 45° to thechannel 36. In low, the disc 88 sits almost perpendicular to the channel36, minimizing the flow rate to the patient. The flow rates are relativeto the exhale flow setting. If the insufflation pressure setting ishigh, the flow will be high. If the insufflation pressure setting islow, the flow will be correspondingly low.

Shown in FIG. 8 is an example display 170 for automatic mode.

The insufflation pressure 184 can be set in the range of 0-50 cmH₂O in 1cmH₂O increments using an increase arrow 186 and decrease arrow 188. Theexsufflation pressure 192 can be set in the range of 0-50 cmH₂O in 1cmH₂O increments using an increase arrow 194 and decrease arrow 196. Theflow rate can be set to high, medium, or low via button 182.

The insufflation time 198, the length of time that the positiveinsufflation pressure is active, can be set in the range of 0-3 sec in0.2 sec increments. The exsufflation time 202, the length of time thatthe negative exsufflation pressure is active, can be set in the range of0-3 sec in 0.2 sec increments. The rest time 204, the length of timebetween exsufflation of one cycle and insufflation of the next cycle,can be set in the range of 0-3 sec in 0.2 sec increments. The number ofcycles 174 can be set in the range of 1-99 using decrement arrow 178 andincrement arrow 180.

Shown in FIG. 9 is an example display 210 for configuration.

The resting positive pressure 212, the positive pressure set during restwhen neither insufflation nor exsufflation is active, can be set in therange of 0-15 cmH₂O in 1 cmH₂O increments using an increase arrow 214and decrease arrow 216.

The user can enable or disable flutter and set the flutter rate 218 inthe range of 0-20 Hz in 1 Hz increments using an increase arrow 220 anddecrease arrow 222. Flutter is disabled when the flutter frequency 218is zero. During insufflation, the oscillator disk 88 is positioned in afixed orientation based on the flow setting. During exsufflation, theoscillator 30 behavior is based on whether flutter is enabled ordisabled. If enabled, the oscillator disk 88 rotates continuously at theset flutter rate. If flutter is disabled, the oscillator disk 88 ispositioned parallel to the channel 36, thereby maximizing flow.

The user can enable or disable a parameter lock. When enabled bypressing the lock button 224, all settings are locked and cannot bechanged without entering a password.

The software monitors the various sensors in the system: the blowertemperature sensor 112, the channel air temperature sensor 116, and thechannel air pressure sensor 120. When any of the sensors indicate thatthere is a problem, such as an out-of-range temperature or pressure, thesystem is immediately switched into an idle state, shutting off theblower, and a message is posted on the display 24 indicating the error.

The software displays information to the user on the touch screen 24 andthe user uses the touch screen 24 to set operating parameters in waysknown in the art. For example, if the user wishes to set theinsufflation pressure, the user touches the insufflation pressuredisplay on the touch screen 24 and the display changes to show up anddown arrows. The user touches the appropriate arrow repeatedly until thedesired setting is reached, the up arrow to increase the pressure andthe down arrow to decrease the pressure. All parameter settings operatesimilarly.

As indicated above, the apparatus 10 has a manual mode and an automaticmode. In manual mode, several parameters must be set prior to operation,as at 240. These parameters include the insufflation pressure 150, theexsufflation pressure 158, the flow rate 148, and the flutter 212 duringexsufflation. Optionally, the cycle count display 144 is reset to zerousing button 146. After the parameters are set, the user touches astart/stop button 142 on the touch screen 24, as at 242, to turn theblower 14 on, as at 244.

An insufflation is initiated by actuating either an inhale button 164 onthe touch screen 24 or the appropriate side of the rocker switch 97 onthe remote 96, as at 246. Insufflation is maintained until the button164 or rocker switch 97 is released, as at 248. An exsufflation isinitiated by actuating either an exhale button 166 on the touch screen24 or the appropriate side of the rocker switch 97 on the remote 96, asat 250. Exsufflation is maintained until the button 166 or rocker switch97 is released, as at 252. At the end of exsufflation, the cycle countdisplay 144 increments to display the number the cycles since the lastreset.

When treatment is complete, the user touches the start/stop button 142on the touch screen 24, as at 254, to turn the blower 14 off, as at 256.

In automatic mode, several parameters must be set prior to operation, asat 260. These parameters include the insufflation pressure 184, theexsufflation pressure 192, the insufflation time 198, the exsufflationtime 202, the rest time 204, the flow rate 182, the flutter duringexsufflation 212, and the number of treatment cycles 174. Optionally,the cycle count display 174 is reset to zero via button 176.

After the parameters are set, the patient touches a start/stop button172 on the touch screen 24, as at 262, to turn the blower 14 on, as at264, and to begin the treatment cycles. As described above, a treatmentcycle includes an insufflation at the set insufflation pressure for theset insufflation time, as at 266, a exsufflation at the set exsufflationpressure for the set exsufflation time, as at 268, and a rest at the setrest pressure for the set rest time, as at 272. At the end of theexsufflation, the cycle count display 174 increments to display thenumber the cycles since the last reset. When the set number of thetreatment cycles is reached, as at 270, the apparatus 10 discontinuestreatment and turns the blower 14 off, as at 274. If the user wishes toabort treatment prior to reaching the end of the last treatment cycle,the user touches the start/stop button 172 on the touch screen 24.

Thus it has been shown and described an apparatus for inducing coughswhich satisfies the objects set forth above.

Since certain changes may be made in the present disclosure withoutdeparting from the scope of the present invention, it is intended thatall matter described in the foregoing specification and shown in theaccompanying drawings be interpreted as illustrative and not in alimiting sense.

1.-6. (canceled)
 7. An apparatus comprising a blower having an intakeand an exhaust, a patient interface, at least one valve having aninsufflation position to couple the exhaust of the blower to the patientinterface so that a positive insufflation pressure is applied to anairway of a patient via the patient interface, the at least one valvehaving an exsufflation position to couple the intake of the blower tothe patient interface so that a negative exsufflation pressure isapplied to the airway of the patient, and a controller to controloperation of the blower and the at least one valve, wherein theapparatus has an automatic mode in which the controller switches the atleast one valve between the insufflation position and the exsufflationposition based on at least one preselected time interval, wherein theapparatus has a manual mode in which the controller switches the atleast one valve between the insufflation position and the exsufflationposition based on a manual input.
 8. The apparatus of claim 7, whereinthe apparatus has a rest mode in which the controller positions the atleast one valve in the insufflation position and operates the blowersuch that a positive rest pressure that is less than the positiveinsufflation pressure is applied to the airway of the patient.
 9. Theapparatus of claim 8, wherein the intake of the blower is operationallyconnected to atmosphere when the valve is in the insufflation position.10. The apparatus of claim 8, wherein the manual input is usable toselect the rest mode.
 11. The apparatus of claim 7, wherein saidcontroller receives parameter settings input by a user, said parametersettings including at least one of an insufflation pressure, anexsufflation pressure, and a rest pressure.
 12. The apparatus of claim11, wherein said blower comprises a variable speed blower and theparameter settings further include a blower speed.
 13. The apparatus ofclaim 11, wherein said parameter setting further include at least one ofan insufflation time, an exsufflation time, and a rest time.
 14. Theapparatus of claim 7, wherein the manual input comprises an inhalebutton coupled to the controller and an exhale button coupled to thecontroller, the valve being in the insufflation position in response tothe inhale button being actuated, and the valve being in theexsufflation position in response to the exhale button being actuated.15. The apparatus of claim 14, wherein said apparatus is in a rest modewhen neither the inhale button nor the exhale button are actuated. 16.The apparatus of claim 7, further comprising a case in which the blower,the valve, and the controller are housed.
 17. The apparatus of claim 16,further comprising a remote control jack coupled to the controller andaccessible at an exterior of the case and further comprising a remotecontrol that is removably coupleable to the remote control jack.
 18. Theapparatus of claim 17, wherein the remote control include a rockerswitch that is movable to control whether the apparatus is in theinsufflation mode or the exsufflation mode.
 19. The apparatus of claim7, further comprising a stepper motor that is signaled by the controllerto control whether the valve is in the insufflation position or theexsufflation position.
 20. The apparatus of claim 7, further comprisinga temperature sensor coupled to the controller, the temperature sensorbeing positioned so as to measure a temperature of the blower.
 21. Theapparatus of claim 7, further comprising a temperature sensor coupled tothe controller, the temperature sensor being positioned so as to measurea temperature of air flowing toward the patient interface.
 22. Theapparatus of claim 7, further comprising a pressure sensor coupled tothe controller, the pressure sensor being positioned so as to measure apressure of air flowing toward the patient interface.